Automatic safety cut-off



R. T. WEBB. AUTOMATIC SAFETY cuLoFr.

APPLICATION FILED JAN.I7, 1921.

L4 l 93 34E. Patented .I une I3, 11922.

attenua@ ROBRT T. 'WEBBq 0F ST. LOUIS, MISSOUR, ASSIGNOR, BY DIRECT AND ll/[ESNE ASSIGN- MENTS, OF ONE-FOURTH TO GEO. 11V. REED, JR., AND ONE-FOURTH TO LYNTDN XFJYANT, F TULSA, OKLAHOIKA.

AUTGMATC SAFETY CUT-OFF.

anlasser.

To @ZZ whom t may concern:

Be it known that l, Ron-Enr T. Vnnn, a citizen or the United States, residing at St. Louis, in the county of St. Louis City and State ot Missouri, have invented new and useful .improvements in Automatic Safety Jut-s, of which the following is speci cation.

rlhis invention relates to an automatic vsafety cut oil for automatically closing a pipe or passage carrying a fluid under pres sure, when such pressure ceases or Hows below a predetermined pressure degree.

Une object of the invention is to provide a simple, compact, satisfactory and sa're means of automatically shutting olii a gas or other fluid pressure supply when the pressure falls below any predetermined value or that required to give sate and satisfactory combustion, or when the supply fails entirely.

A further object of the invention is to provide a valve device for the purpose described, combined with means for resetting the same after closure for further operation and the resumption of the flow ot gas or fluid.

The invention isparticularly designed for use in gas service systems, in which when the gas supply is temporarily cut off or obstructed to the extent that res are extinguished, the outlets are lett open and when the pressure again comes on the is 'free to low out. ln the case ot stoves and tur naces and some other appliances this is very inconvenient and dangerous. This invention provides a valve which is designed to automatically close the outlets under such conditions and thus eliminate the inconveniences and danger such as now commonly exists.

The invention will be better understood by reference to the accompanying drawing, in which Figure 1 is a vertical transverse section through one form of safety cut oit embodying myinvention. y

Figure 2 is a section thereof taken in a plane at right angles to that shown in Figure l.

' Figure 3 is a view in elevation roil the cut offas applied in a gas service system.

Figure l is a sectional view of a modified form of cut oil.

Referring particularly to Figures 1, 2 and Specication of Letters Patent.. Patil/Amig@ Jun@ 135 19220 Application le. January 17, 1921.

Serial No. 437,385.

3 of the drawing, 1 designates a valve shell or casing having an inlet 2 and an outlet 53 separated by a partition l formed with a port and valve seat 5. The said shell or casing is provided with an upstanding tubular portion 6, the lower part of which is suitably formed, as at 7, to term a guide for a vertically movable slidable valve 8, while the upper part thereof is internally threaded to receive a coupling member or plug 9. The coupling member or plug 9 carries a frame portion 10 ot a pressure chamber 11, the sides of which are formed by counterpart detachable cover plates 12. Arranged in proximity to the respective cover plates are pressure diaphragme 13, limited in outward movement by said cover plates.- rlhese diaphragms may be of any suitable construction and marginally secured between the opposed surfaces oit the frame 10 and cover plates 12.

The valve member 8 is suitably formed at its lower end to engage the valve seat and close the port 5,y and is formed at its lower end with a passage 14 communicating with a chamber or socket 15 formed in its upper portion. The said chamber 15 of the hollow valve thus constructed is in communication with a similar chamber 16 inthe hollow plug 9, which is provided at its upper end with a passage 17 connecting said chamber with the pressure chamber 11. A coiled spring 18 is arranged in the chambers 15 and 1G and exerts its expansive pressure to normally force the valve 8 downward to close the port 5, said spring being compressed, however, when the pressure in the chamber 11 is above a predetermined point, to hold the valve elevated oil the scat 5. Willen the valve is raised or unseated gas may iiow from a service pipe 19 through the inlet 2, port 5 and outlet 3 to a pipe or pipes 20 leading to the burner or burners 2l or other parts to be supplied with gas for servicel use. A portion 4of this gas also flows upward through the passage 14, chambers 15 and 16 and passage 17 into the pressure chamber 11, thus forcing the diaphragme 18 outwardly or toward the walls or covers 12. Slide-bly and pivotally connected at their upper ends to the respective diaphragms 13 are bellcranlr leversQQ having at their lower ends short arms 28 which are suitably fulcrumed upon the frame 10, as indicated at 24. Links (one for each lever) are pivotally coupled Cil at their upper ends to the lower ends oit the respective levers 22, as indicated at 2G, and at their lower ends to the valve 8, as indicated at 26, thus independently connecting each lever with the valve. l/Vhen the diaphragms 13 are forced outward, the resulting movement of the levers 22 causes the pivot members 26 to be elevated, thus draw-y ing on the links 25 and raising the valve 8 against the resistance of the spring 18, thus holding the valve open ior service action and thefspring under tension or con'ipression. So long as this condition prevails, under a proper service pressure in the system, the valve will be maintained in open condition and gas may flow to the service l'ixtures ior use in a manner previously explained. lf, however, the pressure in the system should entirely cease or be reduced below a sa'je predetermined pressure, the valve will be moved to closed position by the expansion of the spring and the diaphragms will be moved inward, in an obvious manner. The valve will thus totally cut oil the llow connection between the burner or burners or other service fixtures and the service pipe 19, preventing the inconveniences and dangers arising upon a resumption ot flow oil gas in the system and requiring a manual resetting of the safety cut otf and opening oit the lvalve thereot before service conditions can be resumed. i

ln order to provide for a restoration of service conditions, after the valve 8 has been automatically closed, provide the partition 4 with a by-pass port 27 connecting the inlet 2 and outlet 3, said port being controlled by a rotary plug valve 28 which is normally in closed condition. Said plug is provided with an external linger piece 29 and is normally held closed by a spring 30.

By turning this valve 28 so that its passage registers with the port 27' gas will be allowed to flow between the inlet 2 and outlet 3 into the service system of the houseor building in which the burners and automatic cut off are arranged, and a portion of this gas will flow upwardly into the pressure chamber 1l. `When the pressure in this chamber 11 reaches a predetermined rdegree the diaphragms 13 will again be forced outward. to effect the opening of the valve 8, which will thereafter be held in such condition by the pressure of the gas, as long as such pressure is above the predeter mined minimum limit, thus effecting a resumption of gas service to the burners or appliances to be supplied. l/Vhen this is etfected the valve 28 isV released and the spring 3() automatically returns it to closed position and maintains it in such position until positively operated.

In Figure 8 I have shown the arrangement of the safety cut ott in a service system as described, and in Figure 4 I have shown a modii'ied form o'l' my invention which may be employed under some conditions. ln this modified form of my invention l have disclosed a valve casing laL having an inlet 2a, an outlet 3 and a partition 4tL provided with a kvalve seat port and passage 5a. At its top the valve casing has a tubular portion (SiL internally threaded to receive the externally threaded depending hollow stem 9a of a casing 1l closed at its top by a horizontal detachable cover plate 121K rllhe casing forms a pressure chamber llb and arranged therein is a suitable diaphragm 13 marginally held between the opposed surfaces of the pressure chamber and the cover plate. Secured to the center of this diaphragm is a bracket 3l to which is pivoted the upper end of a link 32, said link being pivoted at its lower end to and within the tubularbody portion of a hollow valve 8, said valve being suitably formed at its lower end for engagement with the seat of the port 5a. Also connected with the bracket 3l is a stem 33 movable through an opening in a threaded plug 34 fitted in the cover plate 12FL and carrying at its upper end a milled knob or finger piece Encompassing the stem 33 between the central portion oit the diaphragm and the lower end of' the plug 34, and properly held and centered thereby, is a coiled spring 36, which is adapted to be compressed on the upward movement of the diaphragm upon the adjustment of the valve 8a to open position under service pressure, and which is adapted when the pressure ceases or flows below the sate minimum limit to expand and press' the diaphragm and link downward and thus shift thev valve 8 to closed position. rlhe operation o1 this device in maintaining the valve open and in automatically closing it to cut oli connection between the service pipe and the burners or fixtures will be readily understood from the' foregoing description. The device may be reset for use, after-the valve has been closed, by the operator pulling upward through the .knob or linger piece 35 on the'stem 33, thereby raising the diaphragm and valve so that gas may flow into the pressure cham` ber until. the desired pressure is reached to maintain the diaphragm and valve in service position.

From the foregoing descriptiointaken in connection with the drawing', the Construction and mode of operation ot my improved automatic safety cut oil will be readily understood, and it will be seen that 'the in-` vention provides a simple, inexpensive7 Vreliable and compact device of this character which maybe readily installed in anygas or other similar service system tor the purpose of automatically cutting off comrnuni` cation between the ixtures to be supplied andthe outside service pipe to prevent the inconveniences and dangers arising loo from the inow of gas, under ordinary conditions, when service flow in the outside system is again resumed. Vith my invention7 as soon as the service pressure ceases or flows below a safe limit, the supply of gas to the liXtures is automatically cut 0E and will be maintained in cut off condition until a person aware of the condition of affairs automatically resets the valve for a resumption of gas flow.

Having thus fully described my invention, I claim:

1. The combination with a iuid pressure service system, of a casing having an inlet and an outlet, a hollow valve for closing communication between said inlet and outlet, a fluid pressure chamber in communication with the inlet through the valve when the valve is opened and closed against communication with the inlet when the valve is closed, a spring operating by eX- pansion to close the valve, a pair of dia phragms in said pressure chamber, links connected to said valve and extending into said pressure chamber, a pair of rock levers connected with said links, and 'the said rock levers being connected with said diaphragme whereby movements of the latter will control the movement of the valve.

2. The combination with a fluid pressure service system, of a casing having an inlet and an outlet, a hollow valve for closing communication between said inlet and outlet, a fluid pressure chamber in communication with the inlet through the valve when said valve is opened and closed against communication with the inlet when the valve is closed, a spring tending normally to close said valve, a pair of oppositely disposed diaphragme in the pressure chamber, links connected to said valve and extending into said pressure chamber, a pair of oppositely disposed bell crank levers in said casing, the ends of certain arms of said levers being secured to the casing and the ends 4of the opposite arms of the levers being connected respectively to said diaphragms, and the intermediate portions of said levers being connected to said links.

ln testimony whereof aiiiX my signature.

ROBERT T. WEBB. 

